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Question #46597
The Question
An ecologist introduces a hyper-specific obligate parasitoid to eradicate an invasive agricultural pest, assuming this biocontrol agent will permanently stabilize the ecosystem. However, after the pest population crashes to near zero, the parasitoid completely vanishes, leading to a subsequent uncontrolled resurgence of the pest. Which driver of biodiversity loss from the 'Evil Quartet' best explains the parasitoid's disappearance, and what ecological vulnerability does this highlight?
Options
- A.
Alien species invasion; the introduced parasitoid disrupted native food webs, leading to its own competitive exclusion.
- B.
Co-extinction; the obligate dependency of the parasitoid on the pest caused its local extinction when the host population fell below a critical survival threshold.
- C.
Over-exploitation; the parasitoid over-exploited the pest, directly violating Gause’s competitive exclusion principle.
- D.
Habitat fragmentation; the rapid decline of the pest population fragmented the biological microhabitat, reducing the parasitoid's carrying capacity.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Biocontrol|Parasitoid|Host|Niche_Partitioning
Why This Question Is Tricky
Common Mistakes
The 'Conceptual Pivot' is applying the concept of 'Co-extinction' (usually taught via mutualism like plant-pollinators or natural host-parasite loss) to the failure of a biological control agent.
Students often assume biocontrol is flawlessly stable (Diversity-Stability hypothesis), failing to realize that hyper-specificity creates a fragile dependency trap where extreme success (pest eradication) guarantees the biocontrol agent's own demise.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Microbes in Human Welfare - Class 12 |
| Concept | Biocontrol Agents Synergy |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |